Hi stockae92.
I think that so long as sounds are being generated, the webpage is working correctly.
The receiver in different watches would have different sensitivities I suppose. I would suggest turning the volume up to maximum. I had the earbuds in direct contact with the caseback (inserting them between a watch pillow and the caseback). You could try this, but again I suppose different watches have the receiver in different positions .
Good luck.
Rgds.